Some Aspects of Pituitary Function after Neuroadenolysis in Patients with Metastatic Cancer

The effects of neuroadenolysis on plasma titres of β-endorphin, β-lipotropin, ACTH, TSH and prolactin have been investigated in five patients with metastatic cancer who responded to the treatment and have been in remission for more than four years and in five others who were undergoing the treatment for the first time for pain due to cancer metastases. β-endorphin, β-lipotropin and ACTH titres were within the normal ranges of values in both categories of patients but post-neuroadenolysis titres of these peptides were higher than those before the treatment. The ability to secrete TSH and prolactin and to respond to thyroid stimulating hormone releasing hormone (TRH) remains intact following the treatment. However, whereas basal TSH titres and response to TRH was lower in the majority of patients, no such effect was observed on prolactin secretion. Plasma titres of prolactin and TSH were below the sensitivity of the method in the five patients who are in remission for more than four years. These preliminary findings suggest that neuroadenolysis probably affects some mechanism(s) associated with the control of β-endorphin, β-lipotropin and ACTH synthesis.

Diffusion of alcohol upon application of neuroadenolysis of the pituitary gland (NALP). An experimental study using HRP and WGA-HRP in the cat

Diffusion of alcohol in neuroadenolysis of pituitary gland (NALP) was observed by injection of horseradish peroxidase (HRP) or wheat germ agglutinin-HRP conjugates (WGA-HRP) into the pituitary of the cat. After small-amount injection of WGA-HRP into the pituitary, WGA-HRP labeling was observed markedly around the third ventricle and the ventral part of the hypothalamus. While, in large-amount injection of WGA-HRP, it extended to all of the ventricular systems and dipped into the substances of the brain and spinal cord through the ependyma. These results suggest that the main site of action for alcohol injected into the pituitary is probably the hypothalamus.

Comparison of the effects of HMG or pure FSH stimulation during suppression with an LHRH agonist analogue

Infertile patients who responded poorly in an in-vitro fertilization programme were treated with human menopausal gonadotrophin (HMG) or with pure follicle stimulating hormone (FSH) during continuous administration of a luteinizing hormone-releasing hormone (LHRH) agonist, to determine whether a low level of LH is required for follicle maturation. No statistically significant differences were detected in the dose of gonadotrophins, duration of treatment, oestradiol and LH levels, numbers of recovered oocytes, transferred embryos or fertilization rates. It is concluded that an absence of low levels of LH does not disturb follicular development in the follicular phase. Based on the low fertilization rates in the present study (0.32 with HMG versus 0.45 with FSH) the authors suggest that, as well as hormonal deficiency, other factors may also influence follicular and early embryonic development.

Aromatase inhibition in hypophysectomised female rats: a novel animal model for in vivo screening

An experimental model for in vivo screening of aromatase inhibitors was developed which overcomes the interference of compounds centrally active via the pituitary-gonad axis. Mature female surgically or chemically hypophysectomised (hypx) rats were treated with the oestrogen precursor dehydroepiandrosterone sulphate (DHEAS), immediately followed by administration of the test compound. During the treatment period vaginal smears were prepared daily. In the hypx rats DHEAS was metabolised to oestrogens, which induced vaginal cornification. By determining oestradiol levels it was shown that the aromatase inhibitors tested antagonised oestrogen synthesis and, as a result, cornification was counteracted. 4-Hydroxyandrostenedione and SH 489 showed equipotent aromatase inhibition, whereas 19-mercapto-androstenedione (ORG 30365) was at least twice as potent as the former compounds. By using various oestrogen precursors the inhibition of the enzyme aromatase was demonstrated. For in vivo screening of compounds on their aromatase inhibiting activity the assay in hypx rats appeared to be very suitable and selective but, because anti-oestrogens also antagonise vaginal cornification, anti-oestrogenic activity has to be excluded.

The duration of pituitary suppression by means of intranasal gonadotropin hormone-releasing hormone analogue administration does not influence the ovarian response to gonadotropin stimulation and success rate in a gamete intrafallopian transfer (GIFT) program

The aim of the study was to compare the ability to prevent endogenous luteinizing hormone interferences, ovarian response, and success rate between two groups of patients undergoing GIFT procedures and treated with the same stimulatory protocol but with a different timing in the administration of the gonadotropin hormone-releasing hormone analogue (GnRH-a). The former underwent a concomitant administration of gonadotropin and analogue; the latter started stimulation only after the achievement of complete hypogonadotropinism. The analogue was always given intranasally and stimulation was identical in the two groups. Our results showed that (1) prevention of premature luteinization is obtained with both approaches and (2) no significant difference in terms of length of stimulation, gonadotropin doses, ovarian response, and success rate was recorded between the two groups.

[Percutaneous ethanol injection of parathyroid adenoma under US guidance]

A patient with post-operative recurrent parathyroid adenoma was treated with percutaneous injection of absolute ethanol under ultrasonographic guidance. Serum calcium and PTH level were both successfully normalized, while recurrent nerve palsy was encountered as side effect. Six months later, she was suffered from hyperparathyroidism again, because of local tumor recurrence. Her recurrent nerve palsy was cured at that time. This technic could be a simple and non-invasive alternative for the conventional surgical procedure, but the indication for larger adenomas like this case should be carefully considered.

Evidence for the involvement of cerebral renin-angiotensin system (RAS) in stress analgesia

Studies concerning variations of the central renin-angiotensin system (RAS) during immobilization stress in rats have shown a significant increase in renin-like activity in the hypothalamus and fronto-parietal cortex, together with a definite decrease in the hypophysis and pineal gland. The resultant stress analgesia is blocked by the previous administration of naloxone and saralasin (angiotensin II antagonist). The intracerebral administration of renin and angiotensin II produces an increase in latencies to thermoalgesic stimuli; this is reduced, as is immobilization stress, by naloxone and saralasin. Both chemical hypophysectomy obtained by dexamethasone pretreatment as well as surgical epiphysectomy block the stress-induced analgesia. The experimental data obtained argue in favour of the participation of the cerebral RAS in stress analgesia through the indirect mechanism of release of opioid peptides.

The treatment of pain in the patient with cancer

Pain is one of the most feared consequences of cancer. Control of pain from cancer should be possible with the approaches discussed above. Changing attitudes toward the effective use of narcotic analgesics, the development of novel routes and methods of administration, and a clinical approach based on scientific principles and humane care offer the promise of improved management of pain in patients with cancer.

The treatment of postmenopausal women with advanced breast cancer with buserelin

Repeated administration of long-acting analogues of gonadotrophin-releasing hormone down-regulates the pituitary gonadotrophins and gonadal hormones. The activity of these compounds in premenopausal women with breast cancer has been previously noted. In an attempt to cause a highly selective medical hypophysectomy 18 consecutive postmenopausal women with symptomatic advanced breast cancer were treated with intranasal buserelin in divided dosages of either 600 or 1000 micrograms daily. The pituitary gonadotrophins were suppressed in all patients, without objective evidence of response. This is in contrast with an earlier finding that the long-acting analogues of gonadotrophin-releasing hormone were effective in postmenopausal patients with breast cancer.

Neurosurgical treatment of chronic pain

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Relief of cancer pain in man: alcohol-induced neuroadenolysis vs. electrical stimulation of the pituitary gland

To explore new methods for the control of intractable pain caused by advanced cancer, the analgesic effect of electrical stimulation of the pituitary gland was investigated in 25 patients. The results were compared with a control study and with the effects of alcohol-induced pituitary neuroadenolysis (NALP) in the same patients. The pain score (0: no pain at all, 4: extreme pain) in the control study was 3.88 +/- 0.33. After electrical stimulation of the pituitary gland it was 1.24 +/- 1.61; and after NALP it was 1.0 +/- 1.60. The pain scores after electrical stimulation and NALP were significantly lower (P less than 0.01) than those in the control study; but there was no significant difference when the two were compared with each other. The duration of pain relief following NALP (59.65 +/- 68.72 days) was significantly longer compared with that recorded following electrical stimulation (2.97 +/- 2.58 days). Autopsy examinations of 3 patients who expired from their malignancies revealed that the pain relief was unrelated to the degree of necrosis induced in the pituitary by alcohol. Naloxone administration did not inhibit the analgesic effect of either NALP or electrical stimulation. The advantages and disadvantages of electrical stimulation, the pain relief mechanism activated by this method, and potential clinical applications are also discussed.

Pain relief after hypophysectomy

Thirteen series of patients who underwent surgical or chemical hypophysectomy for the relief of pain associated with cancer were reviewed. In 10 series, involving 334 patients with breast or prostate cancer, surgical hypophysectomy produced pain relief in 70% of the patients afflicted with either tumor, including some with no evidence of hormone dependence. These results were then compared with the results of chemical hypophysectomy. This procedure was performed in 3 series involving 533 patients, of whom 24% had cancer other than breast or prostate. Chemical hypophysectomy produced pain relief in over 75% of the patients, regardless of tumor type or hormonal dependence. The possible role of the pituitary, the hypothalamus, and endogenous opiates in mediating the pain relief associated with hypophysectomy was examined. The mechanism by which pain relief is achieved remains unclear, but there is significant evidence that this relief is not related directly to the expected fall in the levels of known pituitary hormones. Evidence is provided that pain relief is the result of a hypothalamic pain-suppressing capability triggered by hypophysectomy. On the basis of both clinical data and the mechanism of action, we conclude that surgical and chemical hypophysectomy are fundamentally similar procedures.

Mechanism of neuroadenolysis of the pituitary for cancer pain control

Several theories have been advanced to explain how neuroadenolysis of the pituitary (NALP) relieves cancer pain. Interference with hormonal regulation, interruption of pain pathways and a compensatory overproduction of brain endorphins have been proposed. The purpose of the present experimental study is to determine whether neuronal activity of the pituitary gland, as related to the primary somatosensory cortex (PSC), may be involved in the pain perception pathway influenced by NALP, using EEG and tooth pulp evoked potentials (TPEPs). Pituitary activity showed a high voltage slow activity which slowed after alcohol injection into the sella turcica. When naloxone was injected after NALP, a rhythmic high voltage activity appeared in the pituitary gland. After NALP, the TPEP recorded from the PSC disappeared, while NALP induced an increase in the amplitude of the TPEP in the pituitary gland. An injection of naloxone severely decreased this response in the pituitary gland, in contrast to changes in the PSC where the original response reappeared after an injection of naloxone. Our hypothesis is that an increase of TPEPs (hyperactivity) in the pituitary gland is produced after alcohol wounding (wounding effect), leading to a decrease of pain response in the sensory cortex (decrease of TPEPs). This wound effect may be influenced by endorphins, because naloxone, a specific antagonist of opiate receptors, reversed the changes in TPEPs in both places.

The use of stereotaxic chemical hypophysectomy in the treatment of thalamic pain syndrome

Three patients with neurological injuries consistent with cerebral stroke subsequently developed pain over portions of the body contralateral to the injured hemisphere. Stereotaxic chemical hypophysectomy was used in the management of this pain after other surgical procedures and medical management had failed to provide relief. Postoperatively, all patients were treated for hypopituitarism. All developed transient diabetes insipidus, and one patient developed transient right third nerve palsy. No other complications were encountered. All three patients experienced significant pain relief within 48 hours of the procedure. By the date of discharge, two of the three patients reported complete, and the third greater than 80% pain relief. At the initial follow-up visit all patients were essentially pain-free. These patients have now been followed for 58, 39 and 19 months, and remain free of their original pain. During this time the intravenous administration of naloxone has failed to reproduce the preoperative pain. Pituitary function testing 1 year or more following operation demonstrated that none of the patients had an endocrinologically complete hypophysectomy. Recovery from transient diabetes insipidus was not associated with return of the original pain. The mechanism of action of stereotaxic chemical hypophysectomy in the relief of pain related to thalamic lesions remains unknown. The observation that naloxone failed to reproduce the preoperative pain casts doubt on the theory that augmentation of endogenous opiate release is the primary mechanism. Additional observations suggest that pain relief after hypophysectomy may be more directly the result of stimulation of a hypothalamic pain-suppressing mechanism than due to the elimination of pituitary hormones.

Rat mammary carcinoma regressions during suppression of serum growth hormone and prolactin

Female rats bearing N-nitrosomethylurea-induced mammary carcinomas were treated with pergolide mesylate to suppress serum prolactin. The drug was given alone, or with somatostatin, 20 micrograms/hr delivered by osmotic minipump for 7 days to suppress serum growth hormone. Tumour regressions did not occur with pergolide alone, but did so promptly in all of 5 rats when growth hormone levels were also suppressed by somatostatin. A potent long-acting agonistic analogue of somatostatin, L362,823 produced similar tumour regressions at a dose of 5 micrograms/hr when given with pergolide, but was ineffective alone. This dose completely prevented the episodic release of pituitary growth hormone.